Changed battery, now it won't start.

[yurinaut]

Strange issue. I swapped the battery out for a new BMW battery on my '88 K100RS. Once finished, I started it up and it worked. Shut it down after about 30 seconds (I know, should have let it run longer) and finished putting the tray back in..etc. Now, it won't start. If I let it sit for a few hours it will sputter like it wants to start and then it just won't catch fire.

I thought maybe I had fouled the plugs so I pulled them all (one at a time) and cleaned them and put everything back. Still, same issue.

I have one of the old alarms on it and had to disconnect/reconnect but it started afterwords. Checked all the fuses and they all look fine. It's got about 1/4 of a tank of gas as well. Am I missing something obvious?

Thanks,
Mike

[Teslaesque]

With these bikes, its almost always something obvious...
I know that i've done something similar...cleaned the plugs and it still wouldnt start. Changed the plugs, however, and it fired right up. Maybe pull the plugs, properly ground them/you, and check to see the spark with your own eyes?

[bmwmick]

Strange issue. I swapped the battery out for a new BMW battery on my '88 K100RS. Once finished, I started it up and it worked. Shut it down after about 30 seconds (I know, should have let it run longer) and finished putting the tray back in..etc. Now, it won't start. If I let it sit for a few hours it will sputter like it wants to start and then it just won't catch fire.

I thought maybe I had fouled the plugs so I pulled them all (one at a time) and cleaned them and put everything back. Still, same issue.

I have one of the old alarms on it and had to disconnect/reconnect but it started afterwords. Checked all the fuses and they all look fine. It's got about 1/4 of a tank of gas as well. Am I missing something obvious?

Thanks,
Mike

Yep,
You fouled the plugs with that short run time. Replace them.

[yurinaut]

That's what I thought. I'll pick up a set on the way home. Thanks gentlemen.

-Mike

[BuddingGeezer]

You never said if the plugs were wet or dry. I had a 87 K100LT and the plugs did not fowl with a 30 second run.

It very well could be fouled plugs. I am a proponent of throwing heavy fuel fowled plugs, but if you cleaned them the engine should have started and maybe run rough.

If the new spark plugs doesn't cure it, the red flag in the post to me is "I put the tray back in". Check the fuel injection computer for a good plug connection and no broken wires.

Ralph Sims

[kbasa]

Make sure the big connector on the brain is fully seated.

BTDT.

[yurinaut]

The plugs were a bit wet but it's hard to tell visually if it would have caused it not to start. I got the plugs yesterday and will put them in tonight. If that doesn't work, I'll start looking at the wiring around the tray as Ralph said to do. I'll chime in with the results in the morning. Hopefully, all will be well.

Thanks again,
Mike

[Rpbump]

Make sure that your battery connections are tight along with the connections to your starter. I once had a battery cable that was corroded internally. The cable was very hot where the corrosion was. A new cable was installed solving the problem and the insulation on the bad cable had to be removed so the source of the problem could be seen. Some new batteries should be placed on a trickle charger before installation. :banghead :usa Ride Safe

[deilenberger]

The plugs were a bit wet but it's hard to tell visually if it would have caused it not to start. I got the plugs yesterday and will put them in tonight. If that doesn't work, I'll start looking at the wiring around the tray as Ralph said to do. I'll chime in with the results in the morning. Hopefully, all will be well.

Thanks again,
MikeIf the plugs were wet, the cylinders are still wet, as is the intake tract.


Remove the plugs and leave them out overnight.
Open the throttle fully and lock it open.. leave it that way overnight.
Then put in new plugs, and open the throttle FULLY and hold it OPEN while trying to start the bike. You want max air getting into the cylinders.

Once it fires - leave it running for at least 5 minutes before shutting it off.

[chilibowlfan]

Being new to K bikes, I'm discovering all kinds of idiosyncrasies. Yesterday, I went to start the "Family Truckster" and it would barely turn over. Dead battery? I have a new BMW/Excide battery on the shelf. The K had a new (the dealer said) Westco battery. So I removed the Westco. When I put a voltmeter on the Westco - it read 12.84v. Not Dead! I called a friend who's riden K bikes more than anyone else and asked his advice. He advised that it might be the Westco battery and to replace it with the BMW battery, which I did and the bike fired right up. I've been running Westcos for years in Airheads and Oilheads with no problem. As a matter of fact I got over 5 years service life out of them. Yes a Battery Tender is involved. The K expert also said if that didn't work to check the starter brushes. He said the entire electrical system works through that circuit. However that involves removing the ABS unit and to only do that if the battery change didn't work. So if the problem continues, you may want to check your battery.

Used to be Yellow Bike Mike now Family Truckster Mike

[yurinaut]

Got home last night and checked the connections, all appeared to be okay so, before swapping out the plugs, I attempted to fire it up and yep, it cranked up with no problems. Sigh.... I'm guessing the cylinders were still wet and after sitting for two days waiting for me to get 10 minutes to put the plugs in it dried out.

BTW: I let it warm up fully before shutting down. It was raining something awful or I would have taken it out for a ride just to clear everything out. Maybe today if it stop raining before I get home.

Thanks for all the advice. I may go ahead and swap the plugs anyway. Either way, at least the brick is flying again!!

-Mike